Grease, primarily from residential and commercial kitchens, can cause significant operational issues if not managed properly. This post reviews educating the public on the grease problem, emphasizes restaurant grease trap maintenance, outlines collection system pretreatment programs, and explain how bioaugmentation can assist in grease degradation within biological treatment plants.

Understanding the Grease Problem
Grease, fats, and oils are byproducts of cooking and food preparation. When these substances enter the wastewater system, they tend to solidify and create blockages, leading to backups, overflows, and increased maintenance costs. The impact of grease on wastewater treatment plant comes from the fact that insoluble grease/fatty acids take longer to decompose biologically than other soluble organics and nuisance organisms such as M. parvicella and Nocardia forms (foaming) thrive on grease.

Step 1 - Educating the Public (Keep Grease Out)
Public awareness is the first line of defense against grease-related issues. Programs to educate residents and businesses about the proper disposal of grease helps to reduce the amount entering the wastewater system. Simple actions, such as wiping grease from dishes before washing and disposing of it in the trash, can make a substantial difference. Community outreach programs, informative brochures, and social media campaigns are effective tools for spreading this message.

Step 2 - Restaurant Grease Trap Education & Maintenance
Restaurants and other food service establishments are major contributors to grease in the wastewater system. Proper maintenance of grease traps is crucial to prevent grease from entering the sewer lines. I find it interesting that many restaurant workers do not know about the grease trap and how odors blamed on "dumpsters/trash" is actually coming from a poorly maintained trap. Regular cleaning and inspection ensure that they function correctly. Establishments should also train their staff on best practices for grease management and disposal. By adhering to these practices, restaurants can play a significant role in reducing the grease load on wastewater treatment plants. Grease trap microbial products are often subject to debates regarding their ability to reduce FOG entering the collection system. Data collected in studies has demonstrated that well designed grease trap microbial blends when dosed appropriately along with normal inspection/maintenance helps with trap maintenance and lower grease/long chain fatty acids entering the collection system.

Step 3 - Collection System Pretreatment
Pretreatment programs are essential for managing grease before it reaches the wastewater treatment plant. These programs involve installing and maintaining equipment designed to capture and remove grease from the wastewater. Regular inspections and maintenance of the collection system can prevent grease build-up and ensure the smooth operation of the treatment facility. Pretreatment programs also include regulatory measures, such as permits and inspections, to enforce compliance among businesses that discharge grease-laden wastewater. In problem sections of collection systems, you can use added biological cultures to reduce grease accumulation in pipes and lift stations. A side benefit is these grease control programs can also reduce odors and H2S. These cultures must be added upstream of the problem section and allowed to form a beneficial biofilm on pipe walls. In effect, you are transforming the pipe walls and lift station into a biological pretreatment section.

Can Bioaugmentation Aid in Grease Degradation at the Biological Treatment Plant?
Despite best efforts to minimize grease entry into the wastewater system, some grease inevitably makes its way to the treatment plant. Here, bioaugmentation can play a role in enhancing grease degradation. Bioaugmentation involves introducing specific microorganisms into the biological treatment process. These microorganisms accelerate the degradation of fats, oils, and grease, improving the overall performance of the treatment plant.

Nitrification is one of the most complex and crucial processes within the wastewater microbial community. This biochemical process involves the conversion of ammonia (NH₃) into nitrate (NO₃⁻) and is carried out by a specialized group of microorganisms known as nitrifiers. These nitrifiers can be broadly categorized into two main groups: Ammonia Oxidizing Bacteria (AOB) and Nitrite Oxidizing Bacteria (NOB). Both are slow-growing organisms and require specific environmental conditions to thrive, including relatively narrow ranges of pH, alkalinity, and dissolved oxygen levels.

The Process of Nitrification
Nitrification occurs in two main stages:

• Ammonia Oxidation: In the first stage, ammonia is oxidized to nitrite (NO₂⁻) by AOB. This step is represented by the chemical equation (note the following equations not balanced):
• NH₃ + O₂ → NO₂⁻ + H₂O + H⁺
• This reaction is primarily carried out by bacteria from genera such as Nitrosomonas, Nitrosospira, and Nitrosococcus.
• Nitrite Oxidation: In the second stage, nitrite is further oxidized to nitrate by NOB. The chemical equation for this reaction is:
• NO₂⁻ + O₂ → NO₃⁻
• Common genera involved in this process include Nitrobacter, Nitrospira, and Nitrococcus.
  
  

Environmental Conditions for Optimal Nitrification
The efficiency of nitrification is highly dependent on several environmental factors:

• pH
  ​Nitrifiers operate best within a narrow pH range of 6.5 to 8.5. Deviations outside this range can inhibit their activity and slow down the nitrification process. Acidic or highly alkaline conditions can adversely affect enzyme activity and cellular processes in these bacteria.
• Alkalinity
  Alkalinity acts as a buffer to maintain a stable pH in the system. During nitrification, hydrogen ions (H⁺) are produced, which can lower the pH. Adequate alkalinity is necessary to neutralize these acids and maintain a conducive environment for nitrifiers.
• Dissolved Oxygen
  Both AOB and NOB require dissolved oxygen (DO) for their metabolic processes. Optimal DO levels for nitrification typically range from 2 to 4 mg/L. Insufficient oxygen can lead to incomplete nitrification and the accumulation of intermediate compounds such as nitrite.

Challenges in Nitrification 
Inhibition and Activity Reduction
Facilities often report instances where they believe their nitrifiers have been "killed." However, in many cases, it is more likely that the nitrifiers are experiencing inhibition or a decrease in activity rather than a complete die-off. Factors such as the presence of toxic compounds, sudden changes in environmental conditions, or competition with other microorganisms can inhibit nitrification.

Monitoring and Diagnosis
Before implementing widespread changes, importing sludge from another plant, or adding concentrated nitrifier products, it is crucial to accurately diagnose the state of the nitrifier population. Aster Bio’s qPCR technology offers a powerful tool for this purpose. By quantifying the genetic material of nitrifiers, qPCR provides results within hours rather than days, enabling informed decision-making and reducing the need for costly and time-consuming interventions.

Benefits of qPCR Technology

• Accurate & Rapid Results
  Traditional methods for assessing nitrifier populations, such as culture-based techniques, can take several days to yield results. qPCR technology, on the other hand, delivers rapid and accurate data, allowing for timely adjustments to the treatment process.
• Cost and Time Efficiency
  By providing quick insights into the health and abundance of nitrifiers, qPCR helps facilities avoid unnecessary expenses associated with overhauling treatment processes or importing sludge. This technology enables operators to make targeted interventions based on real-time data, saving both time and money.
  
  

We Can Help
Are you struggling with nitrification in your wastewater treatment plant? Don't let uncertainty slow you down at a cost of $225 per sample, qPCR maintains permit and saves money. Contact Aster Bio’s experts today to learn how our qPCR technology can provide you with the rapid and accurate insights you need to optimize your nitrifier populations and enhance the efficiency of your treatment process. Let us help you save time, reduce costs, and achieve better outcomes for your facility. Contact us for more details at [email protected].

​Wastewater treatment plants often face the challenge of foaming, which can disrupt the treatment process and lead to operational issues. Two common filamentous bacteria responsible for foaming are Nocardia Forms and Microthrix parvicella. Understanding their role and implementing control measures is crucial for maintaining efficient wastewater treatment.
 
Nocardia sp & Gordonia (Nocardia Forms)
Nocardia and Gordonia are genera of filamentous bacteria that thrive in wastewater with high concentrations of fats, oils, and grease (FOG). These bacteria form stable foams that can persist for long periods, causing operational problems such as:

• Reduced settling efficiency: The foam can interfere with the settling of solids, leading to poor sludge quality.
• Increased maintenance: Persistent foam can clog equipment and require frequent cleaning.
• Odor issues: The foam can trap odors, leading to nuisance odors.

 
Microthrix Parvicella
Microthrix parvicella is another filamentous bacterium commonly found in wastewater treatment plants. It prefers environments with low oxygen levels and high concentrations of long-chain fatty acids. The presence of Microthrix parvicella , favored during lower temperature months, can lead to:

• Foam formation: Similar to Nocardia, Microthrix parvicella forms stable foams that can disrupt the treatment process.
• Poor sludge settleability: The foam can reduce the efficiency of sludge settling, leading to increased sludge volume and disposal costs.
• Operational challenges: Persistent foam can cause equipment malfunctions and increase maintenance requirements.

 
Control Measures
To mitigate the impact of foaming filaments on wastewater treatment plants, several control measures can be implemented:

1. Optimizing FOG removal: Reducing the concentration of fats, oils, and grease in the influent can limit the growth of Nocardia. This can be achieved through improved pretreatment processes such as grease traps and skimmers.
2. Maintaining proper aeration: Ensuring adequate oxygen levels in the treatment process can inhibit the growth of Microthrix parvicella. Regular monitoring and adjustment of aeration rates are essential.
3. Chemical dosing: The use of chemicals such as chlorine, hydrogen peroxide, or specific biocides can help control the growth of filamentous bacteria. However, this approach should be used with caution to avoid negative impacts on the overall treatment process.
4. Sludge management: Proper sludge handling and disposal practices can prevent the accumulation of filamentous bacteria. Regular sludge wasting and maintaining appropriate sludge age are important factors. Using molecular testing can track problem populations and help operators adjust wasting rates.
5. Foam control agents: The application of foam control agents, such as silicone-based antifoams, can help reduce foam formation and improve operational efficiency.
   
   

By understanding the triggers of filamentous foaming and implementing effective control measures, wastewater treatment plants can maintain efficient operations and minimize the impact of foaming on the treatment process.
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